it compiles, but I can&#39;t figure out how I&#39;d feed the input to the filter, in that case.<br></blockquote><div><br></div></div><div>Input to Filter would be modeled with: &#39;a -&gt; Filter e b&#39;.</div><div><br>
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<div>I would rename your &#39;runFilter&#39; to &#39;unFilter&#39;, then define a function &#39;runFilter&#39; accepting an initial FilterState.</div><div><br></div><div>Regards,</div><div><br></div><font color="#888888"><div>
- db</div><div><br>
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